Vac uu



B. THOENS.

VACUUM PUMP.

(No Model.)

Pi mented Oct. 27

Ifivezgtor jurfiardf oez w;

UNITED STATES PATENT OFFICE BURCHARD THOENS, on NEW ORLEANS. LOUISIANA.

VACUUM-PUMP.

SPECIPICATIQN forming part of Letters Patent No. 329,241, dated October 27, 1885.

Application filed December 27.1884. Serial No. 151,354. (No model.)

To all whom itmay concern:

Be it known that I, BUROHARD THOENS, a subject of the Emperor of Germany, residing at New Orleans, Louisiana, have invented new and useful Improvements in Vacuum-Pumps, of which the followingis a specification.

My invention relates to apparatus for pro: ducing high vacua, and belongs to that class of such apparatus wherein the movement of a fluid or its removal from the vessel to be exhaustedis caused by the flow of a body of liquid in its vicinity, and its object is to furnish an apparatus capable of speedily and reliably producing vacua of a high degree of attenuation.-

The most common type of apparatus of this general class is the well-known Sprengel droppump, in which the liquid used is allowed to drop through apunched or strangulated opening-from its reservoir, through the drop-tube,

and past theopeuing leading from the vessel-- 'to be exhausted to the drop-tube. .This liquid falls slowly in drops, and with such speedand force only as are due to gravity. The action therefore is necessarily slow, it requiring, with the most approved forms of such v evgn dr p-pumps,and as improved during the past -to keep it in circulation.

few years, several hours to produce a high degree of exhaustion in a small incandescentelectric-lamp globe whose contents are only six to eight cubic inches. This has also confined the use of such pumps within narrow limits, and for small objects, only such as Geissler tubes, incandescent lamps, Urooks radiometer, &c In order, therefore, to produce a pump of much more speedy action, and adapted to be used with much larger objects when desired, I prefer to use what may be termed simply an ejector-pump,wherein the point of communication of the vessel to be exhausted is itself contracted, and is entirely surrounded with a column ofthe exhaustingiluid used, which is itself under a pressure or force exerted upon it by the force-pump used In order to attain still greater rapidity of act.-ion,sevcral injectors are used-one connected to the vessel to be 'above a point which represents the barometric height of the liquid used. This may be betterunderstood by reference to the drawing, in which the figure isa view, partlyin section and partly in elevation, of an appaaflixed to the pipe 8, which leads to and comniunicates with the vessel to be exhausted. The nozzle 13 is of such size rclatively tothe portion of 12 in which it sets that a conc'entric space is formed around it within 12. -Communicative thereto from the branch 5", leading from the pipe 5, through which the liquid used is forced by the pump 2, .is formed an enlargement, 14, so that the fluid is discharged from'b" around 13 in the'shape of a'moving hollow cone. This action, it is known, will produce a suctional effect in the pipe 8,-drawing therefrom the fluid in the vessel it is connected with, and discharging it with the moving liquid in the pipe 9. Thisinsuresa greater rapidity of action than in'the ordinary Sprengel pump, where drops falling act as minute pistons carrying a small modicum of air only before them. v

In order to attain greater rapidity of action,

with it prior to its discharge into 4, auxiliary ejectors or pumps to any desired number may be used, one such being shown in the drawing. This communicates with the drop-pipe 9 at a point below the discharge-nozzle 13 and contraction l2 and above the point of barometric height of the fluid used, which point, of course, will vary, according to the fluid used, from thirty-one inches for mercury to thirtythree feet for water, or a greater height if a still lighter liquid, as oil, be used. v

and also free the air that becomes mingled The construction of the ejector portion is.

similar to that already described, and it is supplied with the necessary liquid by abranch, 5, from 5.

The drop-tube 9 of the first or main ejector should end below-the normal level of the liquid in the tank 4, so as to be sealed thereby against the ingress of air, while it is preferable that the drop tube 9 of the auxiliary ejector should end above such level, in order to discharge 'into the open air, and it may be provided with an outwardlyopening check-valve, in order to close automatically against ingress of air. If several auxiliary ejector-pumps are used, each is connected to the preceding one, as the auxiliary one here shown is connected to the preceding one, and preferably the dropt-ubes of all, excepting the last, should end below the level of the liquid, as does 9.

Any desired liquid-mercurygoil, glycerine, water, dam-may be used, the only variations needed being those of size due to the dill'erent densities and gravities of the liquids. It is evident that the connecting-pipes 10, the auxiliary ejectors, and the supply-tubes 5 may be provided with suitable stopcocks, so that any desired number only of a series of such auxiliaries may be used.

This arrangement produces a vacuum-producing apparatus speedy and reliable in operation for exhausting the globes of incandes cent lamps, evaporating and concentrating liquids, producing rapid evaporation for the production of low temperatures, and various other purposes.

Each ejector'pnmp does its share of work, and by making a partial vacuum below the falling column of its predecessor adds to the efiiciency of such predecessor, while the air or vapor which has become mingled with the liq uid during the passage'of the latter through the main ejector-pump is removed therefrom by the action of the auxiliary ejector-pumps.

The method embodied of treating or using the liquid employed by subjecting it itself to the action of a vacuum apparatus after its passage through the main pump and before it re turns thereto is not new herein claimed, as it will form the subject of a separate application.

Having thus described my invention, what I claim is- 1. In apparatus for producing high vacna, the combination of a main eject-or pump, to which the vessel to be exhausted is connected. and one or more auxiliary ejectonpumps, each having its suction-pipe connected to the drop or discharge pipe of the preceding ejector pump, substantially as described.

2. In apparatus for producing high vacua, the combination of a main ejecto and one or more auxiliary ejectors, each connected with the discharge or drop pipe of the preceding ejector at a point below the dischargenozzlc thereof and above a point representing the barometric height of a column ol'tlie lluid used. substantially as described.

3. In an apparatus for p reducing hi gh vacua,v the combination of a main ejectorpump, one or more auxiliary ejector-pumps, connected as described, supply tubes or branches lead ing thereto, a reservoir or tank for the fluid, and a pump or forcing apparatus for supplying the liquid thcretln-ough under pressure, substantially as described.

In testimony whereof I alllx my signature in presence of two witnesses.

BURGHARD THOEJS.

Witnesses:

FREDERIO Coon, EDWARD J. 13m XLllA in). 

